Reports of personal attacks on climate scientists, including harassment, legal challenges, and even death threats, have created a hostile environment that inhibits the free exchange of scientific findings and makes it difficult for factual information to reach policymakers and the public, the AAAS Board of Directors said in a statement of concern.

“AAAS vigorously opposes attacks on researchers that question their personal and professional integrity or threaten their safety based on displeasure with their scientific conclusions,” the Board said in the statement, which was approved on 28 June.

Scientific progress depends on transparency, the Board said, but “the sharing of research data is vastly different from unreasonable, excessive Freedom of Information Act requests for personal information and voluminous data that are then used to harass and intimidate scientists.”

The Board added: “Scientists and policymakers may disagree over the scientific conclusions on climate change and other policy-relevant topics. But the scientific community has proven and well-established methods for resolving disagreements about research results.” It uses a self-correcting system in which research results are shared and critically evaluated by peers, and experiments are repeated when necessary.

Leading U.S. scientists have complained about threatening communications and abusive e-mails as a result of their research on the climate impact of heat-trapping gases from human activity. In Australia, top climate scientists have been targeted by an unrelenting e-mail campaign that has resulted in police investigation of death threats, according to recent media reports.

Lawmakers and activist groups also have sought detailed disclosure of records from climate researchers. The American Tradition Institute (ATI) has asked the University of Virginia to turn over thousands of e-mails and documents written by Michael E. Mann, a former U-Va. professor and a prominent climate scientist. Virginia Attorney General Ken Cuccinelli, a climate change skeptic, demanded many of the same documents last year in an effort to determine if Mann had somehow defrauded taxpayers in obtaining research grants. ATI also has sued NASA to disclose records detailing climate scientist James Hansen’s compliance with federal ethics and disclosure rules.

“While we fully understand that policymakers must integrate the best available scientific data with other factors when developing policies, we think it would be unfortunate if policymakers became the arbiters of scientific information and circumvented the peer-review process,” the AAAS Board says. “Moreover, we are concerned that establishing a practice of aggressive inquiry into the professional histories of scientists whose findings may bear on policy in ways that some find unpalatable could well have a chilling effect on the willingness of scientists to conduct research that intersects with policy-relevant scientific questions.”